Method for treating the interior surfaces of molds.



. Z rubber, and fi pounds of French chalk dis-.

ALVIN A. SCHMIDT, OF CHICAGO, ILLINOIS.

(I METHOD FOR TREATING No Drawing.

To all whom it may concern:

Be it known that I, ALVIN A. SCHMIDT, a citizen of the United States,residing at Chicago, county of Cook, and State of Illinois, haveinvented a certain new and Im- 1 proved Methodfor Treating the InteriorSurface of Molds, .of which the following -1S a specification.

My invention relates to an improved method fortreating the interiorsurfaces of molds especially adapted for use in molds for makingconcrete or. Portland cementcastings, and has for its object theproduetion of a method for treating the IIItBIIOI" surfaces of molds,whereby clear and sharp castings will be produced.

My invention consists 1n the method hereinafter described and claimed.

The composition consists of 50 pounds of 'e'ar'bon tetra ehlorid, 1pound of para solved cold fol-"at least three weeks. Two or three coatsof this composition should be applied to the interior surfaces of themold. The composition deposits a rubber surface -onthe interior of themold, the tetra 'chlorid partially evaporating.

If desired, this coating may be further treated with oil and allowed tostand for about an hour. Then the mold may be dusted out with Frenchchalk or other dust and is ready for use.

This method may be used on any desired form of mold 'or a mold made ofany desired material with good success. It will be found, if the mold isotherwise properly made, to greatly facilitate the productionSpecification of Letters Patent.

THE INTERIOR SURFACES OF MOLDS.

Patented Aug. 23, 1910.

Application filed September 2,1909. Serial No. 515,898.-

of clear and sharp castings and the separation of the casting from themold.

Vhile I have described the preferred method of procedure and proportionsof ingredients, these may be varied somewhat while still coming withinthe scope of the appended claims. I

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. The method consists in first forming the mold of suitable materialand then treating its interiorsurface with rubber and chalk in carbontetra chlorid, substantially as described.

2. The method of reparing molds which consists in first treatlng theinterior surface of the mold with rubber and chalk dissolved cold incarbon tetra chlorid and then treating said interior surface with lardoil and chalk dust, substantially as described.

3. The method of preparing molds which consists infirst treating theinterior surface of the mold with one pound of para rubber and livepounds of French chalk dissolved cold in fifty pounds of carbon tetrachlorid and then treating said interior surface with lard oil and chalkdust, substantially as described.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALVIN A. SCHMIDT.

Witnesses:

'I-LELEN F. LILLIS,

JOSHUA R. H. Po'rrs.

of preparing molds which

